Auto discovery of network proxies

ABSTRACT

According to one or more embodiments of the disclosure, techniques herein provide for auto discovery of network proxies. In particular, in one embodiment, a controller in a computer network receives, from both source devices and destination devices, corresponding Transmission Control Protocol/Internet Protocol (TCP/IP) information and associated transaction identifiers (IDs) for packets sent by the source devices and for packets received at the destination devices. The controller may then correlate particular source TCP/IP information to particular destination TCP/IP information based on associated transaction IDs being the same, and can compare the correlated source TCP/IP information and destination TCP/IP information in order to determine whether a proxy device exists (e.g., and which particular type of proxy device exists) between the source device and the destination device.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation Application of U.S. patent application Ser. No. 15/800,055, filed on Oct. 31, 2017, entitled AUTO DISCOVERY OF NETWORK PROXIES, by Nataraj, et al., the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to computer networks, and, more particularly, to auto discovery of network proxies.

BACKGROUND

The Internet and the World Wide Web have enabled the proliferation of web services available for virtually all types of businesses. Due to the accompanying complexity of the infrastructure supporting the web services, it is becoming increasingly difficult to maintain the highest level of service performance and user experience to keep up with the increase in web services. For example, it can be challenging to piece together monitoring and logging data across disparate systems, tools, and layers in a network architecture. Moreover, even when data can be obtained, it is difficult to directly connect the chain of events and cause and effect.

In one particular example, it can be difficult to determine the path of traffic between two end points. For instance, in data center “east-west” traffic flows (server to server), there is often a reverse proxy load balancer deployed to balance traffic between application nodes. Without explicit knowledge of the proxy device, it has conventionally been difficult if not sometimes impossible to detect the presence of such proxies. Furthermore, proxy devices such as the reverse proxy load balancer mentioned previously can operate in either a full proxy termination mode (L7/L4 Proxy), or simple Network Address Translation (NAT) packet forwarding mode (L3 Proxy). The monitoring of east-west service traffic requires having knowledge of load balancing deployment mode, as the mode influences debugging workflows. Accordingly, without the awareness of a proxy device's existence, let alone its operational mode, current systems are limited in their ability to properly monitor computer networks and adequately diagnose issues.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments herein may be better understood by referring to the following description in conjunction with the accompanying drawings in which like reference numerals indicate identically or functionally similar elements, of which:

FIGS. 1A-1B illustrate an example computer network;

FIG. 2 illustrates an example computing device/node;

FIG. 3 illustrates an example application intelligence platform;

FIG. 4 illustrates an example system for an application-aware intrusion detection system;

FIG. 5 illustrates an example computing system implementing the disclosed technology;

FIG. 6 illustrates an example of end-to-end communication without knowledge of a network proxy;

FIG. 7 illustrates an example of a simplified packet format;

FIG. 8 illustrates an example of information collection and correlation for auto discovery of network proxies;

FIG. 9 illustrates a specific example of auto discovery of network proxies;

FIG. 10 illustrates an example procedure for auto discovery of network proxies, particularly from the perspective of a controller in a computer network; and

FIG. 11 illustrates another example procedure for auto discovery of network proxies, particularly from the perspective of an agent on a communicating device.

DESCRIPTION OF EXAMPLE EMBODIMENTS Overview

According to one or more embodiments of the disclosure, techniques herein provide for auto discovery of network proxies. In particular, in one embodiment, a controller in a computer network receives, from both source devices and destination devices, corresponding Transmission Control Protocol/Internet Protocol (TCP/IP) information and associated transaction identifiers (IDs) for packets sent by the source devices and for packets received at the destination devices. The controller may then correlate particular source TCP/IP information to particular destination TCP/IP information based on associated transaction IDs being the same, and can compare the correlated source TCP/IP information and destination TCP/IP information in order to determine whether a proxy device exists (e.g., and which particular type of proxy device exists) between the source device and the destination device.

In another embodiment, an agent on a computing device in a computer network captures Transmission Control Protocol/Internet Protocol (TCP/IP) information and associated transaction identifiers (IDs) for packets communicated at the computing device, where the computing device is one of either a source computing device or a destination computing device. The agent may then generate signatures for the packets based on portions of the TCP/IP information that remain unchanged after a layer-3 (L3) network address translation (NAT) proxy device, and then transmits the signatures and associated transaction IDs to a controller in the computer network. Accordingly, the signatures may then cause the controller to i) correlate particular source signatures from the source computing device to particular destination signatures from the destination computing device based on associated transaction IDs being the same, and ii) determine, based on comparing the correlated source and destination signatures, whether a proxy device exists (e.g., and which particular type of proxy device exists) between the source device and the destination device.

Description

A computer network is a geographically distributed collection of nodes interconnected by communication links and segments for transporting data between end nodes, such as personal computers and workstations, or other devices, such as sensors, etc. Many types of networks are available, ranging from local area networks (LANs) to wide area networks (WANs). LANs typically connect the nodes over dedicated private communications links located in the same general physical location, such as a building or campus. WANs, on the other hand, typically connect geographically dispersed nodes over long-distance communications links, such as common carrier telephone lines, optical lightpaths, synchronous optical networks (SONET), synchronous digital hierarchy (SDH) links, or Powerline Communications (PLC), and others. The Internet is an example of a WAN that connects disparate networks throughout the world, providing global communication between nodes on various networks. Other types of networks, such as field area networks (FANs), neighborhood area networks (NANs), personal area networks (PANs), enterprise networks, etc. may also make up the components of any given computer network.

The nodes typically communicate over the network by exchanging discrete frames or packets of data according to predefined protocols, such as the Transmission Control Protocol/Internet Protocol (TCP/IP). In this context, a protocol consists of a set of rules defining how the nodes interact with each other. Computer networks may be further interconnected by an intermediate network node, such as a router, to extend the effective “size” of each network.

Smart object networks, such as sensor networks, in particular, are a specific type of network having spatially distributed autonomous devices such as sensors, actuators, etc., that cooperatively monitor physical or environmental conditions at different locations, such as, e.g., energy/power consumption, resource consumption (e.g., water/gas/etc. for advanced metering infrastructure or “AMI” applications) temperature, pressure, vibration, sound, radiation, motion, pollutants, etc. Other types of smart objects include actuators, e.g., responsible for turning on/off an engine or perform any other actions. Sensor networks, a type of smart object network, are typically shared-media networks, such as wireless or power-line communication networks. That is, in addition to one or more sensors, each sensor device (node) in a sensor network may generally be equipped with a radio transceiver or other communication port, a microcontroller, and an energy source, such as a battery. Generally, size and cost constraints on smart object nodes (e.g., sensors) result in corresponding constraints on resources such as energy, memory, computational speed and bandwidth.

FIG. 1A is a schematic block diagram of an example computer network 100 illustratively comprising nodes/devices, such as a plurality of routers/devices interconnected by links or networks, as shown. For example, customer edge (CE) routers 110 may be interconnected with provider edge (PE) routers 120 (e.g., PE-1, PE-2, and PE-3) in order to communicate across a core network, such as an illustrative network backbone 130. For example, routers 110, 120 may be interconnected by the public Internet, a multiprotocol label switching (MPLS) virtual private network (VPN), or the like. Data packets 140 (e.g., traffic/messages) may be exchanged among the nodes/devices of the computer network 100 over links using predefined network communication protocols such as the Transmission Control Protocol/Internet Protocol (TCP/IP), User Datagram Protocol (UDP), Asynchronous Transfer Mode (ATM) protocol, Frame Relay protocol, or any other suitable protocol. Those skilled in the art will understand that any number of nodes, devices, links, etc. may be used in the computer network, and that the view shown herein is for simplicity.

In some implementations, a router or a set of routers may be connected to a private network (e.g., dedicated leased lines, an optical network, etc.) or a virtual private network (VPN), such as an MPLS VPN thanks to a carrier network, via one or more links exhibiting very different network and service level agreement characteristics.

FIG. 1B illustrates an example of network 100 in greater detail, according to various embodiments. As shown, network backbone 130 may provide connectivity between devices located in different geographical areas and/or different types of local networks. For example, network 100 may comprise local/branch networks 160, 162 that include devices/nodes 10-16 and devices/nodes 18-20, respectively, as well as a data center/cloud environment 150 that includes servers 152-154. Notably, local networks 160-162 and data center/cloud environment 150 may be located in different geographic locations. Servers 152-154 may include, in various embodiments, any number of suitable servers or other cloud-based resources. As would be appreciated, network 100 may include any number of local networks, data centers, cloud environments, devices/nodes, servers, etc.

In some embodiments, the techniques herein may be applied to other network topologies and configurations. For example, the techniques herein may be applied to peering points with high-speed links, data centers, etc. Furthermore, in various embodiments, network 100 may include one or more mesh networks, such as an Internet of Things network. Loosely, the term “Internet of Things” or “IoT” refers to uniquely identifiable objects (things) and their virtual representations in a network-based architecture. In particular, the next frontier in the evolution of the Internet is the ability to connect more than just computers and communications devices, but rather the ability to connect “objects” in general, such as lights, appliances, vehicles, heating, ventilating, and air-conditioning (HVAC), windows and window shades and blinds, doors, locks, etc. The “Internet of Things” thus generally refers to the interconnection of objects (e.g., smart objects), such as sensors and actuators, over a computer network (e.g., via IP), which may be the public Internet or a private network.

Notably, shared-media mesh networks, such as wireless networks, are often on what is referred to as Low-Power and Lossy Networks (LLNs), which are a class of network in which both the routers and their interconnect are constrained: LLN routers typically operate with constraints, e.g., processing power, memory, and/or energy (battery), and their interconnects are characterized by, illustratively, high loss rates, low data rates, and/or instability. LLNs are comprised of anything from a few dozen to thousands or even millions of LLN routers, and support point-to-point traffic (between devices inside the LLN), point-to-multipoint traffic (from a central control point such at the root node to a subset of devices inside the LLN), and multipoint-to-point traffic (from devices inside the LLN towards a central control point). Often, an IoT network is implemented with an LLN-like architecture. For example, as shown, local network 160 may be an LLN in which CE-2 operates as a root node for nodes/devices 10-16 in the local mesh, in some embodiments.

FIG. 2 is a schematic block diagram of an example computing device 200 that may be used with one or more embodiments described herein, e.g., as any of the devices shown in FIGS. 1A-1B above, and particularly as specific devices as described further below. The device may comprise one or more network interfaces 210 (e.g., wired, wireless, etc.), at least one processor 220, and a memory 240 interconnected by a system bus 250, as well as a power supply 260 (e.g., battery, plug-in, etc.).

The network interface(s) 210 contain the mechanical, electrical, and signaling circuitry for communicating data over links coupled to the network 100, e.g., providing a data connection between device 200 and the data network, such as the Internet. The network interfaces may be configured to transmit and/or receive data using a variety of different communication protocols. For example, interfaces 210 may include wired transceivers, wireless transceivers, cellular transceivers, or the like, each to allow device 200 to communicate information to and from a remote computing device or server over an appropriate network. The same network interfaces 210 also allow communities of multiple devices 200 to interconnect among themselves, either peer-to-peer, or up and down a hierarchy. Note, further, that the nodes may have two different types of network connections 210, e.g., wireless and wired/physical connections, and that the view herein is merely for illustration. Also, while the network interface 210 is shown separately from power supply 260, for devices using powerline communication (PLC) or Power over Ethernet (PoE), the network interface 210 may communicate through the power supply 260, or may be an integral component of the power supply.

The memory 240 comprises a plurality of storage locations that are addressable by the processor 220 and the network interfaces 210 for storing software programs and data structures associated with the embodiments described herein. The processor 220 may comprise hardware elements or hardware logic adapted to execute the software programs and manipulate the data structures 245. An operating system 242, portions of which are typically resident in memory 240 and executed by the processor, functionally organizes the device by, among other things, invoking operations in support of software processes and/or services executing on the device. These software processes and/or services may comprise one or more functional processes 246, and on certain devices, an illustrative “proxy detection” process 248, as described herein. Notably, functional processes 246, when executed by processor(s) 220, cause each particular device 200 to perform the various functions corresponding to the particular device's purpose and general configuration. For example, a router would be configured to operate as a router, a server would be configured to operate as a server, an access point (or gateway) would be configured to operate as an access point (or gateway), a client device would be configured to operate as a client device, and so on.

It will be apparent to those skilled in the art that other processor and memory types, including various computer-readable media, may be used to store and execute program instructions pertaining to the techniques described herein. Also, while the description illustrates various processes, it is expressly contemplated that various processes may be embodied as modules configured to operate in accordance with the techniques herein (e.g., according to the functionality of a similar process). Further, while the processes have been shown separately, those skilled in the art will appreciate that processes may be routines or modules within other processes.

——Application Intelligence Platform——

The embodiments herein relate to an application intelligence platform for application performance management. In one aspect, as discussed with respect to FIGS. 3-5 below, performance within a networking environment may be monitored, specifically by monitoring applications and entities (e.g., transactions, tiers, nodes, and machines) in the networking environment using agents installed at individual machines at the entities. For example, each node can include one or more machines that perform part of the applications. The agents collect data associated with the applications of interest and associated nodes and machines where the applications are being operated. Examples of the collected data may include performance data (e.g., metrics, metadata, etc.) and topology data (e.g., indicating relationship information). The agent-collected data may then be provided to one or more servers or controllers to analyze the data.

FIG. 3 is a block diagram of an example application intelligence platform 300 that can implement one or more aspects of the techniques herein. The application intelligence platform is a system that monitors and collects metrics of performance data for an application environment being monitored. At the simplest structure, the application intelligence platform includes one or more agents 310 and one or more servers/controllers 320. Note that while FIG. 3 shows four agents (e.g., Agent 1 through Agent 4) communicatively linked to a single controller, the total number of agents and controllers can vary based on a number of factors including the number of applications monitored, how distributed the application environment is, the level of monitoring desired, the level of user experience desired, and so on.

The controller 320 is the central processing and administration server for the application intelligence platform. The controller 320 serves a browser-based user interface (UI) 330 that is the primary interface for monitoring, analyzing, and troubleshooting the monitored environment. The controller 320 can control and manage monitoring of business transactions (described below) distributed over application servers. Specifically, the controller 320 can receive runtime data from agents 310 (and/or other coordinator devices), associate portions of business transaction data, communicate with agents to configure collection of runtime data, and provide performance data and reporting through the interface 330. The interface 330 may be viewed as a web-based interface viewable by a client device 340. In some implementations, a client device 340 can directly communicate with controller 320 to view an interface for monitoring data. The controller 320 can include a visualization system 350 for displaying the reports and dashboards related to the disclosed technology. In some implementations, the visualization system 350 can be implemented in a separate machine (e.g., a server) different from the one hosting the controller 320.

Notably, in an illustrative Software as a Service (SaaS) implementation, a controller instance 320 may be hosted remotely by a provider of the application intelligence platform 300. In an illustrative on-premise (On-Prem) implementation, a controller instance 320 may be installed locally and self-administered.

The controllers 320 receive data from different agents 310 (e.g., Agents 1-4) deployed to monitor applications, databases and database servers, servers, and end user clients for the monitored environment. Any of the agents 310 can be implemented as different types of agents with specific monitoring duties. For example, application agents may be installed on each server that hosts applications to be monitored. Instrumenting an agent adds an application agent into the runtime process of the application.

Database agents, for example, may be software (e.g., a Java program) installed on a machine that has network access to the monitored databases and the controller. Database agents query the monitored databases in order to collect metrics and pass those metrics along for display in a metric browser (e.g., for database monitoring and analysis within databases pages of the controller's UI 330). Multiple database agents can report to the same controller. Additional database agents can be implemented as backup database agents to take over for the primary database agents during a failure or planned machine downtime. The additional database agents can run on the same machine as the primary agents or on different machines. A database agent can be deployed in each distinct network of the monitored environment. Multiple database agents can run under different user accounts on the same machine.

Standalone machine agents, on the other hand, may be standalone programs (e.g., standalone Java programs) that collect hardware-related performance statistics from the servers (or other suitable devices) in the monitored environment. The standalone machine agents can be deployed on machines that host application servers, database servers, messaging servers, Web servers, etc. A standalone machine agent has an extensible architecture (e.g., designed to accommodate changes).

End user monitoring (EUM) may be performed using browser agents and mobile agents to provide performance information from the point of view of the client, such as a web browser or a mobile native application. Through EUM, web use, mobile use, or combinations thereof (e.g., by real users or synthetic agents) can be monitored based on the monitoring needs. Notably, browser agents (e.g., agents 310) can include Reporters that report monitored data to the controller.

Browser agents and mobile agents are generally unlike other monitoring through application agents, database agents, and standalone machine agents that are on the server. In particular, browser agents may generally be embodied as small files using web-based technologies, such as JavaScript agents injected into each instrumented web page (e.g., as close to the top as possible) as the web page is served, and are configured to collect data. Once the web page has completed loading, the collected data may be bundled into a beacon and sent to an EUM process/cloud for processing and made ready for retrieval by the controller. Browser real user monitoring (Browser RUM) provides insights into the performance of a web application from the point of view of a real or synthetic end user. For example, Browser RUM can determine how specific Ajax or iframe calls are slowing down page load time and how server performance impact end user experience in aggregate or in individual cases.

A mobile agent, on the other hand, may be a small piece of highly performant code that gets added to the source of the mobile application. Mobile RUM provides information on the native mobile application (e.g., iOS or Android applications) as the end users actually use the mobile application. Mobile RUM provides visibility into the functioning of the mobile application itself and the mobile application's interaction with the network used and any server-side applications with which the mobile application communicates.

Application Intelligence Monitoring: The disclosed technology can provide application intelligence data by monitoring an application environment that includes various services such as web applications served from an application server (e.g., Java virtual machine (JVM), Internet Information Services (IIS), Hypertext Preprocessor (PHP) Web server, etc.), databases or other data stores, and remote services such as message queues and caches. The services in the application environment can interact in various ways to provide a set of cohesive user interactions with the application, such as a set of user services applicable to end user customers.

Application Intelligence Modeling: Entities in the application environment (such as the JBoss service, MQSeries modules, and databases) and the services provided by the entities (such as a login transaction, service or product search, or purchase transaction) may be mapped to an application intelligence model. In the application intelligence model, a business transaction represents a particular service provided by the monitored environment. For example, in an e-commerce application, particular real-world services can include a user logging in, searching for items, or adding items to the cart. In a content portal, particular real-world services can include user requests for content such as sports, business, or entertainment news. In a stock trading application, particular real-world services can include operations such as receiving a stock quote, buying, or selling stocks.

Business Transactions: A business transaction representation of the particular service provided by the monitored environment provides a view on performance data in the context of the various tiers that participate in processing a particular request. A business transaction, which may each be identified by a unique business transaction identification (ID), represents the end-to-end processing path used to fulfill a service request in the monitored environment (e.g., adding items to a shopping cart, storing information in a database, purchasing an item online, etc.). Thus, a business transaction is a type of user-initiated action in the monitored environment defined by an entry point and a processing path across application servers, databases, and potentially many other infrastructure components. Each instance of a business transaction is an execution of that transaction in response to a particular user request (e.g., a socket call, illustratively associated with the TCP layer). A business transaction can be created by detecting incoming requests at an entry point and tracking the activity associated with request at the originating tier and across distributed components in the application environment (e.g., associating the business transaction with a 4-tuple of a source IP address, source port, destination IP address, and destination port). A flow map can be generated for a business transaction that shows the touch points for the business transaction in the application environment. In one embodiment, a specific tag may be added to packets by application specific agents for identifying business transactions (e.g., a custom header field attached to an HTTP payload by an application agent, or by a network agent when an application makes a remote socket call), such that packets can be examined by network agents to identify the business transaction identifier (ID) (e.g., a Globally Unique Identifier (GUID) or Universally Unique Identifier (UUID)).

Performance monitoring can be oriented by business transaction to focus on the performance of the services in the application environment from the perspective of end users. Performance monitoring based on business transactions can provide information on whether a service is available (e.g., users can log in, check out, or view their data), response times for users, and the cause of problems when the problems occur.

A business application is the top-level container in the application intelligence model. A business application contains a set of related services and business transactions. In some implementations, a single business application may be needed to model the environment. In some implementations, the application intelligence model of the application environment can be divided into several business applications. Business applications can be organized differently based on the specifics of the application environment. One consideration is to organize the business applications in a way that reflects work teams in a particular organization, since role-based access controls in the Controller UI are oriented by business application.

A node in the application intelligence model corresponds to a monitored server or JVM in the application environment. A node is the smallest unit of the modeled environment. In general, a node corresponds to an individual application server, JVM, or Common Language Runtime (CLR) on which a monitoring Agent is installed. Each node identifies itself in the application intelligence model. The Agent installed at the node is configured to specify the name of the node, tier, and business application under which the Agent reports data to the Controller.

Business applications contain tiers, the unit in the application intelligence model that includes one or more nodes. Each node represents an instrumented service (such as a web application). While a node can be a distinct application in the application environment, in the application intelligence model, a node is a member of a tier, which, along with possibly many other tiers, make up the overall logical business application.

Tiers can be organized in the application intelligence model depending on a mental model of the monitored application environment. For example, identical nodes can be grouped into a single tier (such as a cluster of redundant servers). In some implementations, any set of nodes, identical or not, can be grouped for the purpose of treating certain performance metrics as a unit into a single tier.

The traffic in a business application flows among tiers and can be visualized in a flow map using lines among tiers. In addition, the lines indicating the traffic flows among tiers can be annotated with performance metrics. In the application intelligence model, there may not be any interaction among nodes within a single tier. Also, in some implementations, an application agent node cannot belong to more than one tier. Similarly, a machine agent cannot belong to more than one tier. However, more than one machine agent can be installed on a machine.

A backend is a component that participates in the processing of a business transaction instance. A backend is not instrumented by an agent. A backend may be a web server, database, message queue, or other type of service. The agent recognizes calls to these backend services from instrumented code (called exit calls). When a service is not instrumented and cannot continue the transaction context of the call, the agent determines that the service is a backend component. The agent picks up the transaction context at the response at the backend and continues to follow the context of the transaction from there.

Performance information is available for the backend call. For detailed transaction analysis for the leg of a transaction processed by the backend, the database, web service, or other application need to be instrumented.

The application intelligence platform uses both self-learned baselines and configurable thresholds to help identify application issues. A complex distributed application has a large number of performance metrics and each metric is important in one or more contexts. In such environments, it is difficult to determine the values or ranges that are normal for a particular metric; set meaningful thresholds on which to base and receive relevant alerts; and determine what is a “normal” metric when the application or infrastructure undergoes change. For these reasons, the disclosed application intelligence platform can perform anomaly detection based on dynamic baselines or thresholds.

The disclosed application intelligence platform automatically calculates dynamic baselines for the monitored metrics, defining what is “normal” for each metric based on actual usage. The application intelligence platform uses these baselines to identify subsequent metrics whose values fall out of this normal range. Static thresholds that are tedious to set up and, in rapidly changing application environments, error-prone, are no longer needed.

The disclosed application intelligence platform can use configurable thresholds to maintain service level agreements (SLAs) and ensure optimum performance levels for system by detecting slow, very slow, and stalled transactions. Configurable thresholds provide a flexible way to associate the right business context with a slow request to isolate the root cause.

In addition, health rules can be set up with conditions that use the dynamically generated baselines to trigger alerts or initiate other types of remedial actions when performance problems are occurring or may be about to occur.

For example, dynamic baselines can be used to automatically establish what is considered normal behavior for a particular application. Policies and health rules can be used against baselines or other health indicators for a particular application to detect and troubleshoot problems before users are affected. Health rules can be used to define metric conditions to monitor, such as when the “average response time is four times slower than the baseline”. The health rules can be created and modified based on the monitored application environment.

Examples of health rules for testing business transaction performance can include business transaction response time and business transaction error rate. For example, health rule that tests whether the business transaction response time is much higher than normal can define a critical condition as the combination of an average response time greater than the default baseline by 3 standard deviations and a load greater than 50 calls per minute. In some implementations, this health rule can define a warning condition as the combination of an average response time greater than the default baseline by 2 standard deviations and a load greater than 100 calls per minute. In some implementations, the health rule that tests whether the business transaction error rate is much higher than normal can define a critical condition as the combination of an error rate greater than the default baseline by 3 standard deviations and an error rate greater than 10 errors per minute and a load greater than 50 calls per minute. In some implementations, this health rule can define a warning condition as the combination of an error rate greater than the default baseline by 2 standard deviations and an error rate greater than 5 errors per minute and a load greater than 50 calls per minute. These are non-exhaustive and non-limiting examples of health rules and other health rules can be defined as desired by the user.

Policies can be configured to trigger actions when a health rule is violated or when any event occurs. Triggered actions can include notifications, diagnostic actions, auto-scaling capacity, running remediation scripts.

Most of the metrics relate to the overall performance of the application or business transaction (e.g., load, average response time, error rate, etc.) or of the application server infrastructure (e.g., percentage CPU busy, percentage of memory used, etc.). The Metric Browser in the controller UI can be used to view all of the metrics that the agents report to the controller.

In addition, special metrics called information points can be created to report on how a given business (as opposed to a given application) is performing. For example, the performance of the total revenue for a certain product or set of products can be monitored. Also, information points can be used to report on how a given code is performing, for example how many times a specific method is called and how long it is taking to execute. Moreover, extensions that use the machine agent can be created to report user defined custom metrics. These custom metrics are base-lined and reported in the controller, just like the built-in metrics.

All metrics can be accessed programmatically using a Representational State Transfer (REST) API that returns either the JavaScript Object Notation (JSON) or the eXtensible Markup Language (XML) format. Also, the REST API can be used to query and manipulate the application environment.

Snapshots provide a detailed picture of a given application at a certain point in time. Snapshots usually include call graphs that allow that enables drilling down to the line of code that may be causing performance problems. The most common snapshots are transaction snapshots.

FIG. 4 illustrates an example application intelligence platform (system) 400 for performing one or more aspects of the techniques herein. The system 400 in FIG. 4 includes client device 405 and 492, mobile device 415, network 420, network server 425, application servers 430, 440, 450, and 460, asynchronous network machine 470, data stores 480 and 485, controller 490, and data collection server 495. The controller 490 can include visualization system 496 for providing displaying of the report generated for performing the field name recommendations for field extraction as disclosed in the present disclosure. In some implementations, the visualization system 496 can be implemented in a separate machine (e.g., a server) different from the one hosting the controller 490.

Client device 405 may include network browser 410 and be implemented as a computing device, such as for example a laptop, desktop, workstation, or some other computing device. Network browser 410 may be a client application for viewing content provided by an application server, such as application server 430 via network server 425 over network 420.

Network browser 410 may include agent 412. Agent 412 may be installed on network browser 410 and/or client 405 as a network browser add-on, downloading the application to the server, or in some other manner. Agent 412 may be executed to monitor network browser 410, the operating system of client 405, and any other application, API, or another component of client 405. Agent 412 may determine network browser navigation timing metrics, access browser cookies, monitor code, and transmit data to data collection 460, controller 490, or another device. Agent 412 may perform other operations related to monitoring a request or a network at client 405 as discussed herein including report generating.

Mobile device 415 is connected to network 420 and may be implemented as a portable device suitable for sending and receiving content over a network, such as for example a mobile phone, smart phone, tablet computer, or other portable device. Both client device 405 and mobile device 415 may include hardware and/or software configured to access a web service provided by network server 425.

Mobile device 415 may include network browser 417 and an agent 419. Mobile device may also include client applications and other code that may be monitored by agent 419. Agent 419 may reside in and/or communicate with network browser 417, as well as communicate with other applications, an operating system, APIs and other hardware and software on mobile device 415. Agent 419 may have similar functionality as that described herein for agent 412 on client 405, and may repot data to data collection server 460 and/or controller 490.

Network 420 may facilitate communication of data among different servers, devices and machines of system 400 (some connections shown with lines to network 420, some not shown). The network may be implemented as a private network, public network, intranet, the Internet, a cellular network, Wi-Fi network, VoIP network, or a combination of one or more of these networks. The network 420 may include one or more machines such as load balance machines and other machines.

Network server 425 is connected to network 420 and may receive and process requests received over network 420. Network server 425 may be implemented as one or more servers implementing a network service, and may be implemented on the same machine as application server 430 or one or more separate machines. When network 420 is the Internet, network server 425 may be implemented as a web server.

Application server 430 communicates with network server 425, application servers 440 and 450, and controller 490. Application server 450 may also communicate with other machines and devices (not illustrated in FIG. 3 ). Application server 430 may host an application or portions of a distributed application. The host application 432 may be in one of many platforms, such as including a Java, PHP, .Net, and Node.JS, be implemented as a Java virtual machine, or include some other host type. Application server 430 may also include one or more agents 434 (i.e., “modules”), including a language agent, machine agent, and network agent, and other software modules. Application server 430 may be implemented as one server or multiple servers as illustrated in FIG. 4 .

Application 432 and other software on application server 430 may be instrumented using byte code insertion, or byte code instrumentation (BCI), to modify the object code of the application or other software. The instrumented object code may include code used to detect calls received by application 432, calls sent by application 432, and communicate with agent 434 during execution of the application. BCI may also be used to monitor one or more sockets of the application and/or application server in order to monitor the socket and capture packets coming over the socket.

In some embodiments, server 430 may include applications and/or code other than a virtual machine. For example, servers 430, 440, 450, and 460 may each include Java code, .Net code, PHP code, Ruby code, C code, C++ or other binary code to implement applications and process requests received from a remote source. References to a virtual machine with respect to an application server are intended to be for exemplary purposes only.

Agents 434 on application server 430 may be installed, downloaded, embedded, or otherwise provided on application server 430. For example, agents 434 may be provided in server 430 by instrumentation of object code, downloading the agents to the server, or in some other manner. Agent 434 may be executed to monitor application server 430, monitor code running in a virtual machine 432 (or other program language, such as a PHP, .Net, or C program), machine resources, network layer data, and communicate with byte instrumented code on application server 430 and one or more applications on application server 430.

Each of agents 434, 444, 454, and 464 may include one or more agents, such as language agents, machine agents, and network agents. A language agent may be a type of agent that is suitable to run on a particular host. Examples of language agents include a Java agent, .Net agent, PHP agent, and other agents. The machine agent may collect data from a particular machine on which it is installed. A network agent may capture network information, such as data collected from a socket.

Agent 434 may detect operations such as receiving calls and sending requests by application server 430, resource usage, and incoming packets. Agent 434 may receive data, process the data, for example by aggregating data into metrics, and transmit the data and/or metrics to controller 490. Agent 434 may perform other operations related to monitoring applications and application server 430 as discussed herein. For example, agent 434 may identify other applications, share business transaction data, aggregate detected runtime data, and other operations.

An agent may operate to monitor a node, tier or nodes or other entity. A node may be a software program or a hardware component (e.g., memory, processor, and so on). A tier of nodes may include a plurality of nodes which may process a similar business transaction, may be located on the same server, may be associated with each other in some other way, or may not be associated with each other.

A language agent may be an agent suitable to instrument or modify, collect data from, and reside on a host. The host may be a Java, PHP, .Net, Node.JS, or other type of platform. Language agent may collect flow data as well as data associated with the execution of a particular application. The language agent may instrument the lowest level of the application to gather the flow data. The flow data may indicate which tier is communicating with which tier and on which port. In some instances, the flow data collected from the language agent includes a source IP, a source port, a destination IP, and a destination port. The language agent may report the application data and call chain data to a controller. The language agent may report the collected flow data associated with a particular application to a network agent.

A network agent may be a standalone agent that resides on the host and collects network flow group data. The network flow group data may include a source IP, destination port, destination IP, and protocol information for network flow received by an application on which network agent is installed. The network agent may collect data by intercepting and performing packet capture on packets coming in from one or more network interfaces (e.g., so that data generated/received by all the applications using sockets can be intercepted). The network agent may receive flow data from a language agent that is associated with applications to be monitored. For flows in the flow group data that match flow data provided by the language agent, the network agent rolls up the flow data to determine metrics such as TCP throughput, TCP loss, latency, and bandwidth. The network agent may then report the metrics, flow group data, and call chain data to a controller. The network agent may also make system calls at an application server to determine system information, such as for example a host status check, a network status check, socket status, and other information.

A machine agent may reside on the host and collect information regarding the machine which implements the host. A machine agent may collect and generate metrics from information such as processor usage, memory usage, and other hardware information.

Each of the language agent, network agent, and machine agent may report data to the controller. Controller 490 may be implemented as a remote server that communicates with agents located on one or more servers or machines. The controller may receive metrics, call chain data and other data, correlate the received data as part of a distributed transaction, and report the correlated data in the context of a distributed application implemented by one or more monitored applications and occurring over one or more monitored networks. The controller may provide reports, one or more user interfaces, and other information for a user.

Agent 434 may create a request identifier for a request received by server 430 (for example, a request received by a client 405 or 415 associated with a user or another source). The request identifier may be sent to client 405 or mobile device 415, whichever device sent the request. In embodiments, the request identifier may be created when a data is collected and analyzed for a particular business transaction.

Each of application servers 440, 450, and 460 may include an application and agents. Each application may run on the corresponding application server. Each of applications 442, 452, and 462 on application servers 440-460 may operate similarly to application 432 and perform at least a portion of a distributed business transaction. Agents 444, 454, and 464 may monitor applications 442-462, collect and process data at runtime, and communicate with controller 490. The applications 432, 442, 452, and 462 may communicate with each other as part of performing a distributed transaction. Each application may call any application or method of another virtual machine.

Asynchronous network machine 470 may engage in asynchronous communications with one or more application servers, such as application server 450 and 460. For example, application server 450 may transmit several calls or messages to an asynchronous network machine. Rather than communicate back to application server 450, the asynchronous network machine may process the messages and eventually provide a response, such as a processed message, to application server 460. Because there is no return message from the asynchronous network machine to application server 450, the communications among them are asynchronous.

Data stores 480 and 485 may each be accessed by application servers such as application server 450. Data store 485 may also be accessed by application server 450. Each of data stores 480 and 485 may store data, process data, and return queries received from an application server. Each of data stores 480 and 485 may or may not include an agent.

Controller 490 may control and manage monitoring of business transactions distributed over application servers 430-460. In some embodiments, controller 490 may receive application data, including data associated with monitoring client requests at client 405 and mobile device 415, from data collection server 460. In some embodiments, controller 490 may receive application monitoring data and network data from each of agents 412, 419, 434, 444, and 454 (also referred to herein as “application monitoring agents”). Controller 490 may associate portions of business transaction data, communicate with agents to configure collection of data, and provide performance data and reporting through an interface. The interface may be viewed as a web-based interface viewable by client device 492, which may be a mobile device, client device, or any other platform for viewing an interface provided by controller 490. In some embodiments, a client device 492 may directly communicate with controller 490 to view an interface for monitoring data.

Client device 492 may include any computing device, including a mobile device or a client computer such as a desktop, work station or other computing device. Client computer 492 may communicate with controller 390 to create and view a custom interface. In some embodiments, controller 490 provides an interface for creating and viewing the custom interface as a content page, e.g., a web page, which may be provided to and rendered through a network browser application on client device 492.

Applications 432, 442, 452, and 462 may be any of several types of applications. Examples of applications that may implement applications 432-462 include a Java, PHP, .Net, Node.JS, and other applications.

FIG. 5 is a block diagram of a computer system 500 for implementing the present technology, which is a specific implementation of device 200 of FIG. 2 above. System 500 of FIG. 5 may be implemented in the contexts of the likes of clients 405, 492, network server 425, servers 430, 440, 450, 460, a synchronous network machine 470, and controller 490 of FIG. 4 . (Note that the specifically configured system 500 of FIG. 5 and the customized device 200 of FIG. 2 are not meant to be mutually exclusive, and the techniques herein may be performed by any suitably configured computing device.)

The computing system 500 of FIG. 5 includes one or more processors 510 and memory 520. Main memory 520 stores, in part, instructions and data for execution by processor 510. Main memory 510 can store the executable code when in operation. The system 500 of FIG. 5 further includes a mass storage device 530, portable storage medium drive(s) 540, output devices 550, user input devices 560, a graphics display 570, and peripheral devices 580.

The components shown in FIG. 5 are depicted as being connected via a single bus 590. However, the components may be connected through one or more data transport means. For example, processor unit 510 and main memory 520 may be connected via a local microprocessor bus, and the mass storage device 530, peripheral device(s) 580, portable or remote storage device 540, and display system 570 may be connected via one or more input/output (I/O) buses.

Mass storage device 530, which may be implemented with a magnetic disk drive or an optical disk drive, is a non-volatile storage device for storing data and instructions for use by processor unit 510. Mass storage device 530 can store the system software for implementing embodiments of the present invention for purposes of loading that software into main memory 520.

Portable storage device 540 operates in conjunction with a portable non-volatile storage medium, such as a compact disk, digital video disk, magnetic disk, flash storage, etc. to input and output data and code to and from the computer system 500 of FIG. 5 . The system software for implementing embodiments of the present invention may be stored on such a portable medium and input to the computer system 500 via the portable storage device 540.

Input devices 560 provide a portion of a user interface. Input devices 560 may include an alpha-numeric keypad, such as a keyboard, for inputting alpha-numeric and other information, or a pointing device, such as a mouse, a trackball, stylus, or cursor direction keys. Additionally, the system 500 as shown in FIG. 5 includes output devices 550. Examples of suitable output devices include speakers, printers, network interfaces, and monitors.

Display system 570 may include a liquid crystal display (LCD) or other suitable display device. Display system 570 receives textual and graphical information, and processes the information for output to the display device.

Peripherals 580 may include any type of computer support device to add additional functionality to the computer system. For example, peripheral device(s) 580 may include a modem or a router.

The components contained in the computer system 500 of FIG. 5 can include a personal computer, hand held computing device, telephone, mobile computing device, workstation, server, minicomputer, mainframe computer, or any other computing device. The computer can also include different bus configurations, networked platforms, multi-processor platforms, etc. Various operating systems can be used including Unix, Linux, Windows, Apple OS, and other suitable operating systems, including mobile versions.

When implementing a mobile device such as smart phone or tablet computer, the computer system 500 of FIG. 5 may include one or more antennas, radios, and other circuitry for communicating over wireless signals, such as for example communication using Wi-Fi, cellular, or other wireless signals.

——Auto Discovery of Network Proxies——As noted above, it can be difficult to determine the path of traffic between two end points, such as for data center “east-west” traffic flows where there may be intermediate proxy devices such as a reverse proxy load balancer. Without explicit knowledge of the proxy device, it has conventionally been difficult if not sometimes impossible to detect the presence of such proxies. As also noted above, proxy devices such as the reverse proxy load balancer mentioned previously can operate in either a full proxy termination mode (L7/L4 Proxy), or simple NAT packet forwarding mode (L3 Proxy). The monitoring of east-west service traffic requires having knowledge of load balancing deployment mode, as the mode influences the debugging of workflows.

The techniques herein, therefore, propose a mechanism for auto discovery of network proxies, providing awareness of a proxy device's existence as well as its operational mode, allowing for proper monitoring s and adequate diagnosis of issues, particularly in the context of applications and business transactions. In particular, the techniques herein get information on proxies without communicating with the proxy itself (i.e., based on communication between the two end-points), as opposed to current tools which instead rely on either user inputs or explicit discovery of the proxies which is not feasible in the cloud deployments where the customers don't have access to the underlying network devices.

Specifically, according to one or more embodiments herein, a controller in a computer network receives, from both source devices and destination devices, corresponding Transmission Control Protocol/Internet Protocol (TCP/IP) information and associated transaction identifiers (IDs) for packets sent by the source devices and for packets received at the destination devices. The controller may then correlate particular source TCP/IP information to particular destination TCP/IP information based on associated transaction IDs being the same, and can compare the correlated source TCP/IP information and destination TCP/IP information in order to determine whether a proxy device exists (e.g., and which particular type of proxy device exists) between the source device and the destination device. In another embodiment as described herein, an agent on a computing device (either a source computing device or a destination computing device) captures TCP/IP information and associated transaction IDs for packets communicated at the computing device, and generates signatures for the packets based on portions of the TCP/IP information that remain unchanged after a layer-3 (L3) network address translation (NAT) proxy device. By transmitting the signatures and associated transaction IDs to a controller in the computer network, the controller may then i) correlate particular source signatures from the source computing device to particular destination signatures from the destination computing device based on associated transaction IDs being the same, and ii) determine, based on comparing the correlated source and destination signatures, whether a proxy device exists (e.g., and which particular type of proxy device exists) between the source device and the destination device.

Illustratively, the techniques described herein may be performed by hardware, software, and/or firmware, such as in accordance with the illustrative proxy detection process 248, which may include computer executable instructions executed by the processor 220 to perform functions relating to the techniques described herein, e.g., in conjunction with corresponding processes of other devices in the computer network as described herein.

Operationally, the techniques herein may generally apply to any end-to-end network communication, such as the simplified view of a network 600 shown in FIG. 6 . For example, a source device 610, such as a client device, a first server (e.g., e-commerce or “ECOM” server), or other source device, may communicate packets 640 over a computer network to a destination device 620, such as another client device, a second server (e.g., an order server, a data center server, a content server, a cloud server, etc.). The question to be answered by the techniques herein therefore, is whether a proxy device 630 exists between the source device 610 and destination device 620 (and, in certain embodiments, what type of proxy device it is and/or how the proxy is configured).

According to the techniques herein, having network visibility into each end of the communication allows for monitoring the TCP flows from either end of the potential proxy, and thus determination of the proxy device (e.g., load balancing) deployment mode according to the algorithms described herein. In particular, network agents on each device may monitor the TCP flows to capture information from the TCP packet headers.

As shown in FIG. 7 , a simplified view of a TCP/IP packet 700 (packet 640 above) is shown, where header information comprises a source address 710, source port 720, destination address 730, and destination port 740. As will be readily understood by those skilled in the art, the source and destination addresses may comprise IP information (e.g., IPv4 addresses or IPv6 addresses), while the ports correspond to TCP sessions. Other more specific IP and/or TCP fields may also be present within the header of a packet (or payload 760 when deep packet inspection may be useful), and those shown herein are merely simplified examples. Further, as described above, a transaction ID such as a GUID (or business transaction ID) 750 may also be appended to the header information by the source device (e.g., a network agent), in accordance with the application intelligence platform described herein.

According to the techniques herein, and with reference now to FIG. 8 , source agent 810 (on the source devices) and destination agent 820 (on the destination devices) capture the TCP flow information from packets 640 (such as any of the network agents shown in FIG. 4 above), and transmit the TCP/IP information and associated transaction ID (source information 815 and destination 825) to a controller 850 (e.g., controller 490 of FIG. 4 ) for correlation and comparison as described below.

Notably, the TCP/IP information relayed to the controller may be raw information (e.g., the header information, address/port tuples, etc.), or else may be a computed signature based on the header information. For example, the signatures may be based on header information that remains consistent on either side of the proxy device/load balancer in the case of simple NAT deployment (i.e., the signature may be computed based on header fields that remain unmodified when going through NAT), thus a change would reflect a higher-level proxy change, such as an L4/L7 proxy device operation. For instance, typical load balancer (one type of proxy device) may be configured in multiple fashions: a NAT pass-through where the IP information (e.g., addresses) changes through the proxy, or else in full proxy mode, where new connections are created on either side of the proxy device, thus resulting in a TCP information change (e.g., ports). The signatures may also be more particularly computed based on other specifics, such that determinations may be made into other specific types of proxy device configurations, accordingly.

Once the controller 850 receives the TCP/IP information and BT identifications (raw data or signatures) from both sides of the end-to-end communication, the information may be compared in order to check for matches. That is, by correlating the information according to the identified transactions (e.g., either end of a single business transaction), it can be determined whether the header information has changed in a way that reflects the existence of a proxy device, and particularly, whether the proxy device is a simple L3 NAT or else a full L4/L7 proxy. For instance, if all of the information is the same (same address/port tuple), then no proxy exists. However, if certain information has changed, then it can be determined that a proxy device exists. In one embodiment, in particular, if signatures were created based fields remaining unchanged in an L3 proxy, and those signatures match, then the proxy is a simple L3 NAT, else it is a full L4 proxy.

FIG. 9 illustrates a more detailed (yet still simplified) example of an end-to-end communication network 900 in accordance with one or more embodiments herein. For instance, an app 912 of an ECOM node/server (source device) 910 may communicate (via TCP/IP functions 914) with an app 922 of an ORDER node/server (destination device) 920 (via corresponding TCP/IP functions 924) through a network of L3 switches 932 and 936, an optional firewall 934, and possibly a proxy device such as a load balancer 930. In a proxied communication, the TCP session may break down, where a first session 942 from the source device terminates at a load balancer 930, and then a new session 944 originates at the load balancer (a new source address and port) to the destination address. Accordingly, by correlating the data from the header information captured by respective source agents 916 and destination agents 926 (e.g., where the source agent injects a GUID/BT ID into the packets as described above), the controller 950 can pair both ends of the transaction and compares the TCP/IP information (e.g., signatures). As an example, if the source device sends out packets with source address “S1” and source port “P1” for a particular transaction to destination address “Dl” on destination port “Dl”, yet the destination device receives packets for the particular transaction with source address “S2” (with the same remaining information), then an L3 NAT proxy exists. On the other hand, if the source address and the source port are both changed (e.g., S2 and port “P2”), then it can be determined that an L4/L7 proxy exists. (Notably, depending on whether the proxy device is a forward or reverse proxy, either the source or the destination TCP/IP information may be changed, accordingly.)

According to one or more embodiments herein, various remediation actions may be taken in response to a determination that a proxy device and/or configuration is causing one or more detectable issues, such as delay, packet loss, transaction misdirection, etc.

FIG. 10 illustrates an example procedure for auto discovery of network proxies in accordance with one or more embodiments described herein, particularly from the perspective of a controller in a computer network. For example, one or more non-generic, specifically configured devices (e.g., controllers 850/950 or 490 from FIG. 4 ) may perform procedure 1000 by executing stored instructions. The procedure may start at step 1005, and continues to step 1010, where, as described in greater detail above, a controller receives, from one or more source devices, source TCP/IP information and associated transaction IDs (e.g., BT IDs, GUIDs, etc.) for packets sent by the source device(s). Also, in parallel, in step 1015 the controller is also receiving, from one or more destination devices, destination TCP/IP information and associated transaction IDs for packets received at the destination device(s). Notably, as described above, the source and destination TCP/IP information may be received from source agents on the source devices and destination agents on the destination devices, respectively.

In step 1020, the controller may then correlate particular source TCP/IP information to particular destination TCP/IP information based on associated transaction IDs being the same (i.e., matching the packet from both sides of a transaction), and then in step 1025 may compare the correlated source TCP/IP information and destination TCP/IP information in order to determine, in step 1030 based on the comparing, whether a proxy device exists between the source device and the destination device. For instance, as described above, the comparison may be based on a signature created based on TCP/IP packet header information that remains unchanged after an L3 NAT proxy device (or one that changes differently after an L3 NAT proxy device than after an L4/L7 proxy device). The signatures may generally be computed by the source agents and destination agents (such that receiving the source and destination TCP/IP information in steps 1010 and 1015 comprises receiving signatures from the source agent and the destination agent), though they may also be computed by the controller prior to the comparison is made.

Based on the comparison in step 1030, it can be determined in step 1035 that no proxy device exists between the source device and the destination device in response to the correlated source TCP/IP information and destination TCP/IP information being the same.

On the other hand, in step 1040, it can be determined that a proxy device does exist between the source device and the destination device in response to the correlated source TCP/IP information and destination TCP/IP information being different. Specifically, as described above, an L3 NAT proxy device may be determined to exist between the source device and the destination device in response to the correlated source TCP/IP information and destination TCP/IP information having different IP information but the same TCP information. Also, as described above, existence of one of either an L4 or L7 proxy device (referred to as “L4/L7”, generally) may be determined to exist in step 1040 in response to the correlated source TCP/IP information and destination TCP/IP information having different TCP information.

Notably, the techniques herein may also be configured to determine whether an L3 NAT proxy is a forward or reverse proxy. In particular, it can be determined that the L3 NAT proxy device is a reverse proxy in response to the destination TCP/IP information having a same source address as the source TCP/IP information but a different destination address from the source TCP/IP information. Alternatively, it could be determined that the L3 NAT proxy device is a forward proxy in response to the destination TCP/IP information having a same destination address as the source TCP/IP information but a different source address from the source TCP/IP information.

The illustrative simplified procedure 1000 may end in step 1045, though notably with the option to continue receiving information from source and destination devices (agents) and making determinations as to the existence of proxy devices, or the new or otherwise changed configurations of proxy devices as described herein.

Additionally, FIG. 11 illustrates another example procedure for auto discovery of network proxies in accordance with one or more embodiments described herein, particularly from the perspective of an agent on a communicating device. For example, one or more non-generic, specifically configured devices (e.g., an agent 810, 820, 916, 926, any agent shown in FIG. 4 , etc.) may perform procedure 1100 by executing stored instructions. The procedure may start at step 1105, and continues to step 1110, where, as described in greater detail above, an agent on a computing device captures TCP/IP information and associated transaction IDs for packets communicated at the corresponding computing device (either a source computing device or a destination computing device). The agent may then either send the raw TCP/IP information as described above, or, as shown in step 1115, may generate signatures for the packets based on portions of the TCP/IP information that remain unchanged after an L3 NAT proxy device, as also described in detail above. (Note that in one embodiment the signature may change differently after an L3 NAT proxy device than after an L4/L7 proxy device, in order to differentiate between no proxy, an L3 NAT proxy, and an L4/L7 proxy).

In step 1120, the agent may then transmit the signatures (or raw TCP/IP info) and associated transaction IDs to a controller in the computer network. As described above (and with example reference to procedure 1000 of FIG. 10 ), the signatures may thus cause the controller to i) correlate particular source signatures from the source computing device to particular destination signatures from the destination computing device based on associated transaction IDs being the same, and ii) determine, based on comparing the correlated source and destination signatures, whether a proxy device exists between the source device and the destination device. The procedure 1100 may then illustratively end in step 1125, though notably with the ability to continue monitoring and capturing new information for new packets, and transmitting the signatures/raw info to the controller, accordingly.

It should be noted that certain steps within procedures 1000 and 1100 may be optional as described above, and the steps shown in FIGS. 10-11 are merely examples for illustration, and certain other steps may be included or excluded as desired. Further, while a particular order of the steps is shown, this ordering is merely illustrative, and any suitable arrangement of the steps may be utilized without departing from the scope of the embodiments herein. Moreover, while procedures 1000 and 1100 are described separately, certain steps from each procedure may be incorporated into each other procedure, and the procedures are not meant to be mutually exclusive.

The techniques described herein, therefore, provide for auto discovery of network proxies. In particular, the techniques herein are able to ascertain information about proxy device usage and configuration without explicit knowledge of the proxy and without communicating with the proxy device. That is, through communication with the end-points (e.g., source and destination agents), the existence of a proxy device can be interpreted based on the correlated information (e.g., TCP footprints), notably without requiring any deep packet inspection (DPI).

Knowing whether there is a proxy device, as well as what type of proxy device it likely is, is particularly beneficial for network monitoring and troubleshooting. For instance, if there is an issue with a network (e.g., a particular business transaction/GUID), it can be useful to pinpoint whether the issue occurs before, after, or on a load balancer, as opposed to merely “somewhere” between the two end-points. Changes in network configuration may also be monitored and detected, such as changing configuration from an L3 NAT to a full L4/L7 proxy, therefore being able to correlate newly arising problems to a network configuration change between the end-points.

In still further embodiments of the techniques herein, a business impact of proxy device configurations and changes can also be quantified. That is, because of issues related to proxy configurations (e.g., lost traffic, slower servers, overloaded network links, etc.), various business transactions may have been correspondingly affected (e.g., online purchases were delayed, page visits were halted before fully loading, user satisfaction or dwell time decreased, etc.). The techniques herein, therefore, may compare different proxy configurations (e.g., from different client devices, different web browsers, etc.) to show any effect (e.g., value lost, transactions lost, visits missed, revenue difference, etc.) due to the proxy configurations on various network segments.

While there have been shown and described illustrative embodiments that provide for auto discovery of network proxies, it is to be understood that various other adaptations and modifications may be made within the spirit and scope of the embodiments herein. For example, while certain embodiments are described herein with respect to certain types of networks in particular, the techniques are not limited as such and may be used with any computer network, generally, in other embodiments. Moreover, while specific technologies, protocols, and associated devices have been shown, such as Java, TCP, IP, and so on, other suitable technologies, protocols, and associated devices may be used in accordance with the techniques described above. In addition, while certain devices are shown, and with certain functionality being performed on certain devices, other suitable devices and process locations may be used, accordingly. That is, the embodiments have been shown and described herein with relation to specific network configurations (orientations, topologies, protocols, terminology, processing locations, etc.). However, the embodiments in their broader sense are not as limited, and may, in fact, be used with other types of networks, protocols, and configurations.

Moreover, while the present disclosure contains many other specifics, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Further, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

For instance, while certain aspects of the present disclosure are described in terms of being performed “by a server” or “by a controller”, those skilled in the art will appreciate that agents of the application intelligence platform (e.g., application agents, network agents, language agents, etc.) may be considered to be extensions of the server (or controller) operation, and as such, any process step performed “by a server” need not be limited to local processing on a specific server device, unless otherwise specifically noted as such.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in the present disclosure should not be understood as requiring such separation in all embodiments.

The foregoing description has been directed to specific embodiments. It will be apparent, however, that other variations and modifications may be made to the described embodiments, with the attainment of some or all of their advantages. For instance, it is expressly contemplated that the components and/or elements described herein can be implemented as software being stored on a tangible (non-transitory) computer-readable medium (e.g., disks/CDs/RAM/EEPROM/etc.) having program instructions executing on a computer, hardware, firmware, or a combination thereof. Accordingly this description is to be taken only by way of example and not to otherwise limit the scope of the embodiments herein. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the embodiments herein. 

What is claimed is:
 1. A method, comprising: receiving, at a controller in a computer network from a source device, source Transmission Control Protocol/Internet Protocol (TCP/IP) information and associated transaction identifiers (IDs) that are indicative of a distributed business transaction for packets sent by the source device; receiving, at the controller from a destination device, destination TCP/IP information and associated transaction IDs that are indicative of the distributed business transaction for packets received at the destination device; correlating, at the controller, particular source TCP/IP information to particular destination TCP/IP information based on associated transaction IDs being the same; comparing, at the controller, the correlated source TCP/IP information and destination TCP/IP information to determine whether header information of the correlated source TCP/IP information and destination TCP/IP information remains unchanged after a layer-3 (L3) network address translation (NAT) proxy device; and determining, at the controller based on the comparing, a) whether a proxy device exists between the source device and the destination device and b), if the proxy device exists, a type and a network layer location of the proxy device.
 2. The method as in claim 1, wherein determining whether a proxy device exists comprises: determining that no proxy device exists between the source device and the destination device in response to the header information of correlated source TCP/IP information and destination TCP/IP information being the same; and determining that a proxy device does exist between the source device and the destination device in response to the header information of the correlated source TCP/IP information and destination TCP/IP information being different.
 3. The method as in claim 1, wherein determining whether a proxy device exists comprises: determining that a layer-3 (L3) network address translation (NAT) proxy device exists between the source device and the destination device in response to the header information of the correlated source TCP/IP information and destination TCP/IP information having different IP information but the same TCP information; and determining that one of either a layer-4 or layer-7 (L4/L7) proxy device exists between the source device and the destination device in response to the header information of the correlated source TCP/IP information and destination TCP/IP information having different TCP information.
 4. The method as in claim 3, further comprising: determining that the L3 NAT proxy device is a reverse proxy in response to the destination TCP/IP information having a same source address as the source TCP/IP information but a different destination address from the source TCP/IP information; and determining that the L3 NAT proxy device is a forward proxy in response to the destination TCP/IP information having a same destination address as the source TCP/IP information but a different source address from the source TCP/IP information.
 5. The method as in claim 1, wherein the source TCP/IP information and destination TCP/IP information each comprise either an IPv4 or an IPv6 packet.
 6. The method as in claim 1, wherein the associated transaction IDs are appended to the header information of the correlated source TCP/IP information and destination TCP/IP information.
 7. The method as in claim 1, wherein receiving the source and destination TCP/IP information comprises receiving the source and destination TCP/IP information from a source agent on the source device and a destination agent on the destination device, respectively.
 8. A tangible, non-transitory, computer-readable medium storing program instructions that cause a controller in a computer network to execute a process comprising: receiving, from a source device, source Transmission Control Protocol/Internet Protocol (TCP/IP) information and associated transaction identifiers (IDs) that are indicative of a distributed business transaction for packets sent by the source device; receiving, from a destination device, destination TCP/IP information and associated transaction IDs that are indicative of the distributed business transaction for packets received at the destination device; correlating particular source TCP/IP information to particular destination TCP/IP information based on associated transaction IDs being the same; comparing the correlated source TCP/IP information and destination TCP/IP information to determine whether header information of the correlated source TCP/IP information and destination TCP/IP information remains unchanged after a layer-3 (L3) network address translation (NAT) proxy device; and determining, based on the comparing, a) whether a proxy device exists between the source device and the destination device and b), if the proxy device exists, a type and a network layer location of the proxy device.
 9. The computer-readable medium as in claim 8, wherein determining whether a proxy device exists comprises: determining that no proxy device exists between the source device and the destination device in response to the header information of correlated source TCP/IP information and destination TCP/IP information being the same; and determining that a proxy device does exist between the source device and the destination device in response to the header information of the correlated source TCP/IP information and destination TCP/IP information being different.
 10. The computer-readable medium as in claim 8, wherein determining whether a proxy device exists comprises: determining that a layer-3 (L3) network address translation (NAT) proxy device exists between the source device and the destination device in response to the header information of the correlated source TCP/IP information and destination TCP/IP information having different IP information but the same TCP information; and determining that one of either a layer-4 or layer-7 (L4/L7) proxy device exists between the source device and the destination device in response to the header information of the correlated source TCP/IP information and destination TCP/IP information having different TCP information.
 11. The computer-readable medium as in claim 10, wherein the process further comprises: determining that the L3 NAT proxy device is a reverse proxy in response to the destination TCP/IP information having a same source address as the source TCP/IP information but a different destination address from the source TCP/IP information; and determining that the L3 NAT proxy device is a forward proxy in response to the destination TCP/IP information having a same destination address as the source TCP/IP information but a different source address from the source TCP/IP information.
 12. The computer-readable medium as in claim 8, wherein the source TCP/IP information and destination TCP/IP information each comprise either an IPv4 or an IPv6 packet.
 13. The computer-readable medium as in claim 8, wherein the associated transaction IDs are appended to the header information of the correlated source TCP/IP information and destination TCP/IP information.
 14. The computer-readable medium as in claim 8, wherein receiving the source and destination TCP/IP information comprises receiving the source and destination TCP/IP information from a source agent on the source device and a destination agent on the destination device, respectively.
 15. An apparatus, comprising: one or more network interfaces to communicate with a computer network; a processor coupled to the network interfaces and configured to execute one or more processes; and a memory configured to store a process executable by the processor, the process when executed configured to: receive, from a source device, source Transmission Control Protocol/Internet Protocol (TCP/IP) information and associated transaction identifiers (IDs) that are indicative of a distributed business transaction for packets sent by the source device; receive, from a destination device, destination TCP/IP information and associated transaction IDs that are indicative of the distributed business transaction for packets received at the destination device; correlate particular source TCP/IP information to particular destination TCP/IP information based on associated transaction IDs being the same; compare the correlated source TCP/IP information and destination TCP/IP information to determine whether header information of the correlated source TCP/IP information and destination TCP/IP information remains unchanged after a layer-3 (L3) network address translation (NAT) proxy device; and determine, based on the comparison, a) whether a proxy device exists between the source device and the destination device and b), if the proxy device exists, a type and a network layer location of the proxy device.
 16. The apparatus as in claim 15, wherein to determine whether a proxy device exists comprises: determining that no proxy device exists between the source device and the destination device in response to the header information of correlated source TCP/IP information and destination TCP/IP information being the same; and determining that a proxy device does exist between the source device and the destination device in response to the header information of the correlated source TCP/IP information and destination TCP/IP information being different.
 17. The apparatus as in claim 15, wherein to determine whether a proxy device exists comprises: determining that a layer-3 (L3) network address translation (NAT) proxy device exists between the source device and the destination device in response to the header information of the correlated source TCP/IP information and destination TCP/IP information having different IP information but the same TCP information; and determining that one of either a layer-4 or layer-7 (L4/L7) proxy device exists between the source device and the destination device in response to the header information of the correlated source TCP/IP information and destination TCP/IP information having different TCP information.
 18. The apparatus as in claim 17, the process further comprising: determine that the L3 NAT proxy device is a reverse proxy in response to the destination TCP/IP information having a same source address as the source TCP/IP information but a different destination address from the source TCP/IP information; and determine that the L3 NAT proxy device is a forward proxy in response to the destination TCP/IP information having a same destination address as the source TCP/IP information but a different source address from the source TCP/IP information.
 19. The apparatus as in claim 15, wherein the source TCP/IP information and destination TCP/IP information each comprise either an IPv4 or an IPv6 packet.
 20. The apparatus as in claim 15, wherein the associated transaction IDs are appended to the header information of the correlated source TCP/IP information and destination TCP/IP information. 